Basically it means your PGF installation is waaay old. Like from 2007 if you run Ubuntu 8.04 as I happen to. If you want to find out what your version is compile this short tex file:
\listfiles
\documentclass[]{article}
\usepackage{tikz}
%\usetikzlibrary{positioning}
\begin{document}
a
\end{document}
(found in http://old.nabble.com/I-can’t-find-file-`pgflibrarytikzpositioning.code.tex’-td20634766.html)
After that grab a fresh copy from http://sourceforge.net/projects/pgf/. As root remove (or back up somewhere else) /usr/share/texmf/tex/context/pgf , /usr/share/texmf/tex/generic/pgf , /usr/share/texmf/tex/latex/pgf and /usr/share/texmf/tex/plain/pgf. Extract the new pgf and copy the corresponding folders to the same places, run (as root) mktexlsr and you are done.
Hello , I have a Fedora 14 installation and was facing the same problem. I had seen the tag “It works in Debian” , but still I tried your procedure. But it did not work, I am still getting the same error. Do you know how to resolve this problem for Fedora 14 distribution ?
The same solution works just as well in FC14 (just tried)
Hi Michele, I’m glad it worked for you too.
Hi Adrian, sorry I forgot to thank you … never too late: thanx!
works for Red hat 6 (professional)
I had to run the command texhash in terminal after which it ran perfectly. Thank!
Cool, I’m glad it worked for you too.
Thank you, you saved my day!